Method and apparatus for producing alpha spray mixture of liquid and gas



m 3 1932. W, CARTER 1,856,316

METHOD AND APPARATUS FOR PRODUCING A SPRAY MIXTURE OF LIQUID AND GAS Filed April 17, 1928 l mented May 33, 1932 UNITED STATES PATENT OFFICE "WILLIAM ZDU'UGLAS "CARTIER, F CALDWELL, NEW JERSEY IMTTTIJEEUD 1WD .llt'lEPlhIRATUl-El FOR PRODUCING A $PRA'Y MIXTURE OF LIQUID AND GAS Application filed Aprfl 17,

This invention relates to that class of to tary air-compressors described in my copending application, Serial No. 9i,712 with which several independent streams of liquid and gas are pumped simultaneously by a single impeller, and it combines in the impeller novel liquid'pumping means of the friction-impelling type, in such a manner as to pump siimiltaneously several independent m streams cooperating to produce a spray of m adapted to use in connection with oil burners wherein a small quantity of oil is mixed With a much larger volume of air, and the combustible mixture so formed, is sprayed into a furnace. Tn order to obtain a steady the it is important that a uniform proportion of air and oil be maintained.

This object is best accomplished by dividing the combined air and oil pumping service into its elementary duties. For instance, a

liberal amount of oil is entrained from the t re source of supply by one pumping element and deposited in a local oil sump; a proportion of this oil is pumped continuously from the sump into the pump casing to maintain a seal for the air-pumping impeller, and to supply the burner spray nozzle which is fed through'a needle-valve by the centrifugal force of the oil rotating in the casing. EX- cess oil in the pump casing is returned as through a scoop conduit or aperture to the sump, and excess oil in the sump is pumped baclr to the source of supply by still another pumping element. Tn this Way, since the oil handled by each of the pumps is considerably in encess of the amount consumed by the burner, any ordinary influence tending to affect the flow of 011 (such as varymg Oll level in storage tank, slight stoppages, or air leaks in pipe lines, etc.) Will not affect the amount of oil whirling 1n the casing, and will therefore not affect the amount of air pumped nor the quantity of oil admitted through the needle-valve to the tire.

The method employed to feed oil into the till air stream is important in that the high ve- 1928. Serial No. 270,707.

lo'city of the rotating oil adjacent to the needle-mlve effectively prevents stoppage through coagulation or otherwise at this point, and the relatively low centrifugal force created by this angular velocity, is ample to feed a small quantity of oil into the air discharge-passage Without resorting to the useof a small restricted orifice likely to clog.

Une object of this invention is to effect, with one moving part, the pumping of several independent streams of liquid or of liop uid and air.

Another object is to obtain a uniform spraying mixture of a liquid and gas.

Another object is to provide a pump Which will be self-priming after the initial priming thereof, Without the use of check-valves, and under pumping conditions wherein the source of supply may be either above or below the level of the pump.

Another object is to separate the air and oil ports so as to prevent the uncontrolled lealr age from one into the other.

Another object is to provide a pump from which the ,oil will not siphon after it stops operating.

Another object is to provide a pumping apparatus Which will not flood from pipe drainage after it stops pumping, and which will not discharge an abnormally rich mix ture when starting.

Another object is to provide a pump of the friction impelling type having a scoop for supplying liquid under pressure to the friction impelling face of the rotor.

Other objects will appear.

This invention consists of the parts, and the construction and combination of parts, as hereinafter more full described and claimed, having reference to the accompanying drawings, in which Figure I is a transverse section of my pump taken on line A-A of Fig. TI and looking toward the air-valve side of the pump. The

impeller is partly broken away to show the valve openings in the casing-head.

l igure II is a longitudinal section of the pump taken on line BB of Fig. I.

Figure III is a transverse section taken on -Elli line (3-0 of Figure II looking toward the oil-pumping side of the pump, with the impeller removed.

Figure IV is a side view of the impeller showing the toothed friction grooves for pumping oil.

Figure V is a schematic sectional view of the toothed friction circle formed in the impeller, together with cooperating arcuate channel and connection ports formed in the casing end-plate of the pump.

Referring to the drawings in detail, 1 is a pocketed wheel or impeller mounted on the rotatable drive shaft 2 which is supported in bearings 3 and 4. Impeller 1 consists of hub 5 with circular disc-like sides 6 and 7 attached to the ends of the hub, and having a number of radially disposed vanes 8 connecting the discs 6 and 7 and the hub 5 so as to form pockets 9 between the vanes, the discs, and the hub. Air ports 10 through disc 7 connect the pockets 9, at intervals during their rotation,

I with arcuate inlet and outlet ports 11 and 12 respectively in stationary head 13.

Disc 6 has formed in its outer face the toothed friction circles 14 and 15 arranged concentrically with the axis of the impeller. These friction circles, in their preferred form, consist of a series of teeth 16 arranged in a circle so as to form a large number of cavities between the teeth as shown in Figs. IV and V, although other forms of friction surfaces may be substituted effectively. (lo-operating with the friction circles are the arcuate channels 17, 18 and 19 formed in the end-plate 20. Channels 17 and 18 cooperate with friction circle 14, and channel 19 with friction circle 15.

21 (see Fig. III) is a small groove in the inside face of end-plate 2O communicating with channel 18. This groove extends outward in a direction opposite to the flow of liquid in the casing and serves as a scoop to convey a small amount of liquid into channel 18 to prime the latter when startlng the pump. 23 is a similar groove serving as a scoop to prime channel 19. The broken line 46 indicates the positior tf the impeller with reference to the channels.

Also formed in end-plate 20 are the main oil-inlet port 24, the surplus-oil discharge port 25, passages 26, 27 and 28, and supply channel 29. Formed in the base 30 is a sump 31. 32 is a small conduit connecting passage 27 to a point near the bottom of the sump; and 33 is a large conduit similarly connecting the lower part of the sump with passage 28.

40 is an open-end casing, in the preferred form having a cylindrical bore with its axis 45 eccentrically disposed with relation to the axis of the impeller, and having its ends closed by the head 13 and end-plate 20 which are bolted at 41 to the casing. The width of the casing is such as to separate the head 13 and end-plate 20 sufiiciently to allow a snug running clearance at the sides of the impeller. Scoop 34 communicates with passage 35 in head 13, which passage in turn communicates with the sump 31. 36 is a needle-valve which is controlled by turning the stem 37 which is threaded into the head 13.- lVhen the pump is operating the inner cylindrical surface of the oil is represented by the line 38 in Fig. I and the normal level when the pump is idle may be represented by the horizontal line 39.

42 is the main air intake port which communicates across the upper part of sump 31 with air passage 43 which in turn communicates with the inlet port 11. 44 is the discharge port for the air and oil mixture.

The operation of my pump is as follows: The pump is primed initially by being filled with oil to the level indicated by the line 39, above which level the oil will overflow through port 11 and air passage 43 into the sump 31. After each period of opera-- tion oil will remain in the casing 40 at a level' not higher than line 39, and any oil in the pipes connecting with the source of supply may drain into the casing and overflow into the sump.' .Since all suction and discharge openings in the'pump are above the level39 Where air can reach them through the clearance between the impeller and end-plate, it is obvious that siphoning of oil from the pump casing is impossible.

A motor or other suitable driving, means is connected to shaft 2. hen the impeller starts to rotate the oil in the casing is thrown against the cylindrical wall of the casing and carried around in the form of a circular ring of oil. This ring cannot fill the center of the casing beyond the cylindrical surface indicated approximately by the line 38, at which surface it will flow through scoop 34 into the sump. This amount of oil has been predetermined as the right quantity for producing the best air pumping result-the action of whirling ring of oil in the casing extend inward to line 38 but only that enough oil be present to reach the open ends of grooves 21 and 23 and prime the channels so that the pumping of oil will begin.

The supply pumping channel 17 is located below the normal starting level of the oil in the casing and so will ordinarily be primed for starting. However another priming groove similar to 21 and 23 may be supplied to provide a continuous priming effect on channel 17 when pumping conditions require it.

The oil in channel 17 is moved by the friction of the teeth in friction circle 14, and discharged into the sump. The displacement till teasers of this oil from the channel 17 induces a flow of oil from the source of supply (not shown in the drawings) through oil-inlet port 24 to replace the priming oil so discharged; and since the process is continuous, a constant stream of oil is poured into the sump. In a similar manner the friction circle 14 in passing over the narrow channel 18, entrains a smaller amount of oil from sump 31 through the small conduit 32, and discharges this oil through channel 29 into the casing 40. hannel 13 is primed by the still smaller priming groove 21. Obviously the pumping capacity of the channels is reduced somewhat by the displacement of the priming liquid entering through the priming grooves, but this loss is small in proportion to the total volume handled.

The oil in the casing is maintained in rotation by the vanes 8 in impeller 1, and this oil is discharged through scoop 34 and passage as to the sump as soon as the cylindrical surface indicated by line 38 is reached. In this way the proper amount of oil is maintained in casing l0. After the initial priming enough oil remains in the casing to reprime the channels each time the pump is started, so that the pump is self-priming.

To carry otf excess oil from sump 31 another friction circle is provided in the disc 6 of impeller 1, and a cooperating channel 19, concentric with and of smaller diameter than channels 17 and 18, is formed in the end-plate 20. This friction circle sucks a ny oil tending to rise above the level 22 in the sump, and discharges it through port and a connecting pipe line (not shown) back to the source of supply. The pumping capacity of the channel 19 is purposely made somewhat larger than that of the supply pump channel 17 so that there can be no possibility of flooding the sump 28.

Needle-valve 36 controls an opening from the outer part of the casing into the air dis charge port la. The purpose of this valve is to admit a definite amount of oil from the whirling ring of oil in the casing elO, to the air discharge port where it is picked up bythe air and discharged in an atomized con dition through a pipe and nozzle into the furnace. The centrifugal force created by the rotating impeller induces this flow through the needlewalvc, and the high velocity of the oil adjacent to the valve creates the necessary agitation to prevent stoppage of the opening.

It is important that the oil forming this whirling ring (or liquid piston) be changed continually to prevent the gradual accumulation of sediment and heavy matter in the casing through the centrifugal separation of such matter from the lighter part of the oil. The circulation of oil herein described and the feeding of oil through the needlevalve 36 accomplish this object.

The air-pump part of this unit operates as follows:

The impeller, revolving in the direction indicated by the arrow in Fig. I, rotates the oil by means of vanes 8, thereby causing the oil to assume the shape of a ring which is confined so as to revolve about the axis of the casing 10. The inner cylindrical surface of the oil at 38 is determined by the position of overflow scoop 3d as before stated.

Since impeller 1 rotates on the axis of shaft 2 which is eccentric to axis 45 of the casing 40, it is obvious that the rotating oil enters more deeply into pockets 9 as the pockets on the upper half of the impeller move toward the right. The oil acts as a piston expelling the air from the inner ends of the pockets tlirough the air ports 10 as they register with outlet port 12. Similarly, as the pockets on the lower half of the impeller move toward the left, the oil recedes from the pockets thereby entraining air through the air ports 10 as they come into register with air inlet port 11. In this manner a continuous flow of air maintained from the intake port 42, upper part of sump 31, passage 43, inlet port 11, through air-ports 10 to pockets 9 of the impeller; and outward again through airports 10, outlet port 12 and discharge port 44 to the burner nozzle, or other pointof application not shown in the drawings.

I am aware that prior to my invention in dividual air pumps of the eccentric type, and liquid pumps of the friction impelling type have been built. I do not claim therefore all of the individual constructions in detail, but the method and combinations as follows:

1. In a rotary pump, the combination of a casing, having a liquid inlet port formed therein, an air-pumping impeller rotatably mounted in the casing by rotation of which a ring of liquid is made to rotate about the periphery of the impeller, the casing having independent air-ports formed in one side thereof cooperating with the impeller to convey air to and from the impeller, the impeller having liquid suction means formed therein communicating with said liquid inlet ports to entrain liquid to the impeller, said ring of liquid preventing the leakage of air from the air-ports to the liquid suction means.

2. In a rotary spray pump, the combination of a casing for holding a rotating ring of liquid, an impeller mounted so as to rotate in the casing, the impeller having radially disposed vanes for rotating the liquid, the casing being so disposed with relation to the axis of the impeller as to direct the rotating liquid toward and away from the axis so alternately to entrain and compress air between the vanes, the casing having airports formed in one side thereof cooperating with the impeller to convey air to and from the impeller, the impeller having liquid pumping means formed therein cooperating with the opposite side of the casing so as to prevent leakage of air from the air-ports to the liquid-pumping means.

3. In an air and liquid pump of the rotary type, the combination of an air-pumping impeller having a roughened friction surface formed thereon, a casing enclosing the impeller, the casing having air ports formed therein communicating with the impeller, and also having independent liquid inlet and discharge ports with a communicating channel formed therebetween, the channel being located in close proximity to the friction surface of the impeller so as to confine liquid to a path against the friction surface whereby liquid is impelled by friction to flow through the channel and liquid ports simultaneously with the flow of air through air ports,

4. In a rotary air-pump, a circular casing, a rotatable air-pumping impeller eccentrically mounted in the casing, the casing having a channel formed in the inside wall thereof adjacent to the impeller, the impeller having a friction surface formed thereon cooperating with the channel to impel liquid by friction through the channel, a liquid inlet-port formed in the casing for conveying liquid to the channel and a conduit means communicating with the channel for conveying liquid from the channel into the casing.

5. In a rotary air-pump requiring a liquid seal as described, the combination of an airpumping impeller having a friction surface formed thereon, a casing enclosing the impeller, the casing having a liquid inlet port communicating with a channel formed therein, the channel being located in close proximity to the friction surface so as to confine liquid to a path against the friction surface in order to entrain liquid by friction through the inlet port, conduit means adapted to convey liquid from the channel to the cas ng so as to supply the liquid seal for the air-pumpin 'im eller and a scoo conduit in the easing communicating with the channel so as to prime the channel by conveying liquid from the seal to the channel.

6. .In rotary air pump, the combination of a casing for holding a revolving ring of liquid, the casing having air-ports and liquidports formed therein, an impeller having radially disposed vanes, the impeller be ng rotatably m'iunted in the casing in close proximitv to the ports and on an axis eccentric to the axis of the revolving ring of liquid so that the vanes will advance into and w thdraw from the ring of liquid and thereby alternately expel and entrain-air through the air-ports from and into the space formed between the vanes, the casing having arcuate channels formed therein concentric to the axis of the impeller and communicating with the liquid ports, the impeller having toothed friction circles formed therein cooperating with the channels to impel liquid through the channels, whereby both air and liquid are pumped simultaneously at independent pressures.

7. In a rotary air-pump of the eccentric type, a circular casing, the casing having a channel formed in the inside wall thereof, an air-pumping impeller rotatably mounted in the casing adjacent to the wall, the impeller having a toothed friction circle formed therein cooperating with the channel to impel liquid by friction through the channeha liquid inlet port formed in the casing for conveying liquid to the channel, a conduit communicating with the channel for conveying liquid from the channel to the casing, the casing also having an air-inlet and an air-outlet formed therein, and adjustable means for admitting liquid from the casing to the air outlet.

8. In-a rotary air-pump, the combination of a circular casing for holding a revolving ring of liquid, the casing having air-ports and liquid ports formed therein, an impeller having radially disposed vanes, the impeller being rotatably mounted in the casing in close proximity to the ports and on an axis eccentric to the axis of the casing so that the vanes will advance into and withdraw from the ring of liquid and thereby alternately expel and entrain air through the air ports from and into the space formed between the vanes, the casing having a pair of arcuate channels formed therein concentric to the axis of the impeller and communicating with the liquid channels to impel liquid through the chan-' nels, whereby both air and liquid are pumped simultaneously at independent pressures, the casing having a passage formed therein for conveying liquid from one of the channels into the casing,and conduit means for conveying surplus liquid from the casing to the inlet end of the other channel so as to maintain a uniform supply of liquid in the casing. 9. In a rotary pump of the friction-impelling type, a rotatably mounted impeller, a toothed friction circle formed in the face of the impeller around the axis of rotation, a casing enclosing the impeller, an inside wall of the casing being in close proximity to the face of the impeller containing the friction circle, a plurality of channels with communicating ports formed in the wall opposite the friction circle so as to confine liquid to a path against the friction circle, the channels being of different cross-sectional areas so as to convey different quantities of liquid independently through the several channels when impelled by the same friction circle, the impeller also having formed therein pockets opening at the periphery and communicating air-ports formed near the center thereof, cooperating inlet and outlet ports formed in the casing and registering at intervals with i is lttl

llll

t? it the air-ports so as to convey air to and from the poclrets, the inside periphery of the casing lheing undulating with respect to the routing pocltets so as to direct the liquid radi into and out of the pocltets so as alter nately to expel and entrain air through the airports when the liquid in the casing is 1'0- tated hy the impeller,

l0. la a rotary pump of the frictiondm polling type, a stationary casing, the casing having an arcuate channel formed in the inside wall thereof and an inlet port communieating with the channel, an impeller mounted so to rotate in the casing in close proximity to the wall thereof, the impeller having a fric tion surface formed in the face thereof cooperating with and substantially closing the open side of the channel so as to impel fluid by friction through the channel and port, and scoop priming means communicating with the channel for conveying priming liquid from the casing to the channel.

ll. lln a rotary pump of the friction-i111 polling type, a stationary member, the staonary member having a pumping channel formed in a wall thereof and inlet and outlet ports communicating with the pumping channel, a rotatably mounted impeller, the impeller having a friction surface formed in a face thereof cooperating with and substantially c osing the open side of the pumping channel so as to impel fluid by friction through the pumping channel and ports, the tionary member having additional loranch channels communicating with the pumping channel for circulating a restricted quantity of priming fluid through the pumping channel so as to maintain the priming of the pinup.

l2. lln a rotary pump of the friction-um polling type, a stationary casing, the casing having two or more independent arcuate channels formed on the same radius in the same inside wall thereof and independent inlit and discharge ports communicating with each channel, an impeller mounted so as to rotate in, the casing in close proximity to the wall thereof, a friction surface formed in the face of the impeller cooperating with and substantially closing the open sides of the several channels so as to impel fluid by f1 iction through the several channels and ports at different pumping heads.

'lll. lln a rotary pump of the friction-impolling type, a rotatably mounted impeller, a toothed friction circle formed in a face of the impeller aroundthe axis of rotation, a casing enclosing the impeller, an inside surface of the casing being in close proximity to the face of the impeller containing the friction circle. a plurality of channels with independent communicating ports for each channel formed in the wall opposite the friction circle so as to confine fluid to paths against the friction circle, the channels be ing of different cross-sectional areas so as to convey different quantities of fluid independently through the several channels when impelled by the same friction circle.

14. In a rotary pump of the friction-impelling type, a casing, the casing having two or more independent channels formed in the inside wall thereof and independent inlet and discharge ports connecting each channel, an impeller in the casing rotatably mounted with respect to the casing and located in close proximity to the wall of the casing, a single friction circle formed in the face of the impeller cooperating with and substantially closing the open sides of the several channels so as to impel fluid through the several channels and ports at different pumping heads.

15. lln a rotary pump of the friction-impelling type, a stationary casing having two or more concentric arcuate channels formed in the same side wall thereof and independent inlet and discharge ports connecting each channel, an impeller mounted so as to rotate in the casing in close proximity to said side wall, concentric friction circles formed in the side face of the impeller cooperating with and substantially closing the open sides of the channels so as to impel fluid by friction through the several channels and ports at diflerentpumping heads.

16. In a rotary pump, a casing, the casing having formed in an inside face thereof a plurality of arcuate channels with independent inlet and outlet ports communicating with each channel, an impeller rotatably mounted in the casing, the impeller having formed therein a friction surface cooperating with and substantially closing the open sides of the channel so as to impel a plurality,

of independent streams of liquid through the channels and ports.

17. In a spray pump, a casing having a gas inlet opening and an independent liquid inlet opening and a discharge opening formed therein, an impeller rotatably mounted in the casing by rotation of which a ring of liquid is made to rotate about the periphery of the impeller, the impeller having gas ports formed in one side thereof communicating with the gas inlet opening, liquid suction means cooperating with the oppositeside of the impeller and communicating with the liquid inlet opening, the ring of liquid serving to prevent leakage of gas from the gas ports to the suction means.

18. 'l he process of producing a continuous sprav mixture of liquid and gas consisting of rotating the liquid in a suction pump of the friction -impel'ling type, compressing the gas with the rotating liquid therein, utilizing the energy of the rotating liquid to feed some of the liquid into the gas, and further utilizing said energy to inject a small amount of the liquid into the suction pump to prime the-suc- Hill tion pump and thereby maintain continuity of the process.

19. In a rotary spray pump, the combination of a sump-casing having an opening communicating with the atmosphere, an impeller-cas'ing for holding a rotating ring of liquid, an impeller mounted so as to rotate in the impeller-casing, the impeller having radially disposed vanes for rotating the liq- 1 uid the impeller-casing being so disposed with relation to the axis of the impeller as to direct the rotating liquid towardand away from the axis so as alternately to entrain' and compress air between the vanes, the impeller-casing having air-ports formed therein cooperating with the impeller to convey air to and from the'impeller, the impeller having liquid pumping means formed therein cooperating with main suction and discharge ports and auxiliary passages formed in the casings whereby a substantially constant quantity of liquid is maintained in the impeller-casing.

20. The method ofv producing a uniform 2 spray mixture of combustible liquid and air consisting of rotating the liquid in a partly filled casing whereby a complete ring of liquid of substantial depth having an inner free surface is formed, compressing the air against 80 said surface, feeding a portion of said ring of liquid into said air to form the combustible constituent of said mixture, and addin a substantially continuous supply of liqui to said ring of liquid so as to maintain a sub- 5 stantially constant volume of liquid in said ring of liquid and thereby to produce a uniform spray mixture output.

21. In a rotary pump of the friction-impelling type, a stationary member having a 4 pumping channel formed in a wall thereof, a rotatably mounted impeller, said impeller having a friction surface formed in a face thereof cooperating with and substantially closing the open side of said pumping channel so as to impel liquid by friction through said pumping channel, said impeller also having separate air-pumping pockets formed in the periphery thereofand air ports formed near the center of said impeller communicating with said pockets, and a stationary air-conduit means closely cooperating with said impeller to convey air from said ports simultaneously with the pumping of liquid through said channel. WILLIAM DOUGLAS CARTER; 

